Cadmium Ions' Trace-Level Detection Using a Portable Fiber Optic-Surface Plasmon Resonance Sensor

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Cadmium (Cd) pollution is a global environmental concern due to its severe health impacts, including kidney damage, cancer, and cardiovascular diseases.
• Accurate and sensitive detection of cadmium ions (Cd2+) in water is crucial for environmental monitoring and public health protection.

Purpose of the Study:

• To develop and compare three functionalization strategies for a gold-coated fiber optic-surface plasmon resonance (FO-SPR) sensor for sensitive Cd2+ detection.
• To evaluate the performance of bovine serum albumin (BSA), chitosan, and polyaniline (PANI) as functionalization agents for Cd2+ sensing.

Main Methods:

• Fabrication of a gold-coated reflection-type FO-SPR sensor.
• Functionalization of the sensor surface with BSA, chitosan, and PANI.
• Detection and quantification of Cd2+ using the functionalized FO-SPR sensors.
• Confirmation of Cd2+ presence using X-ray photoelectron spectroscopy (XPS).

Main Results:

• The BSA-functionalized FO-SPR sensor demonstrated high sensitivity for Cd2+ detection, achieving a limit of detection (LOD) in the nanomolar (nM) range.
• XPS analysis confirmed the presence of Cd2+ on the sensor surface for all functionalization strategies.
• The BSA-functionalized sensor exhibited superior performance compared to chitosan and PANI functionalizations.

Conclusions:

• The BSA-functionalized FO-SPR sensor is a sensitive, rapid, cost-effective, and portable tool for detecting trace amounts of cadmium in water.
• This sensor technology holds significant potential for real-time monitoring of cadmium contamination in environmental and potable water sources.